For an example, one can send binary data as either a Blob or an ArrayBuffer using WebSockets.
var file = document.querySelector('input[type="file"]').files[0];
connection.send(file);
Currently server sent events (SSE) don't have the binary messaging capability.
Can I know HTTP/2 protocol supports for sending binary messages? (References would be better)
Related
Is this bidirectional stream native to http2? I looked at various http2 client. I couldn't find any example where it allows the client and server to establish a single connection and continuously push messages from both side.
(For http2 maybe on a lower level, the communications between client/server just had one tcp connection and all the request/responses are multiplexed in it, but from application level can't find any example where you establish a single connection object, and that connection object can be reused to push messages to each other).
So how did grpc achieve "Bidirectional streaming RPCs"? Specifically in this document
https://grpc.io/docs/what-is-grpc/core-concepts/
It indicates that the server side could define a Bidirectional streaming RPC, and it allows both the client and server side to continuously push messages, and achieve features that is websocket like.
Yes, bidirectional streaming is native to HTTP/2. You can read RFC-7540 for the details of how the protocol works, but basically it allows you to create several streams on a single TCP connection, and each stream can send data in either direction independently of each other.
I'm not familiar with all of the HTTP/2 libraries out there, but I know that nghttp2 will allow this in C++, and I think Java and Go have HTTP/2 implementations in their standard libraries.
I am having below requirements with respect to http2.
1) While intiating client side http connection, I should be able to set Max_concurrent_streams supported by http2 server, and handle failure conditions accordingly.
2) Get stream ID of stream and assign priorities.
I checked okhttp client and Java11 http client. But couldnt find any way to achieve the same.
Please let me know is there any way to achieve these.
If you need to deal with low-level details of the HTTP/2 protocol, you can use Jetty's HTTP2Client.
Note that it's the server that decides the max number of concurrent streams it can support, and the client cannot modify that value.
The client can send to the server the max number of concurrent streams it supports, but that number refers to the pushed streams that the server can send to the client.
Using the HTTP2Client APIs you will have easy access to the stream id and will be able to send to the server PRIORITY frames to assign (and modify) priorities to requests.
This is a simple example of how to use HTTP2Client.
You can find more examples in this directory.
What are the major differences between WebSocket and STOMP protocols?
This question is similar to asking the difference between TCP and HTTP. I shall still try to address your question, its natural to get confused between these two terms if you are beginning.
Short Answer
STOMP is derived on top of WebSockets. STOMP just mentions a few specific ways on how the message frames are exchanged between the client and the server using WebSockets.
Long Answer
WebSockets
It is a specification to allow asynchronous bidirectional communication between a client and a server. While similar to TCP sockets, it is a protocol that operates as an upgraded HTTP connection, exchanging variable-length frames between the two parties, instead of a stream.
STOMP
It defines a protocol for clients and servers to communicate with messaging semantics. It does not define any implementation details, but rather addresses an easy-to-implement wire protocol for messaging integrations. It provides higher semantics on top of the WebSockets protocol and defines a handful of frame types that are mapped onto WebSockets frames. Some of these types are...
connect
subscribe
unsubscribe
send (messages sent to the server)
message (for messages send from the server) BEGIN, COMMIT, ROLLBACK
(transaction management)
WebSocket does imply a messaging architecture but does not mandate the use of any specific messaging protocol. It is a very thin layer over TCP that transforms a stream of bytes into a stream of messages (either text or binary) and not much more. It is up to applications to interpret the meaning of a message.
Unlike HTTP, which is an application-level protocol, in the WebSocket protocol there is simply not enough information in an incoming message for a framework or container to know how to route it or process it. Therefore WebSocket is arguably too low level for anything but a very trivial application. It can be done, but it will likely lead to creating a framework on top. This is comparable to how most web applications today are written using a web framework rather than the Servlet API alone.
For this reason the WebSocket RFC defines the use of sub-protocols. During the handshake, the client and server can use the header Sec-WebSocket-Protocol to agree on a sub-protocol, i.e. a higher, application-level protocol to use. The use of a sub-protocol is not required, but even if not used, applications will still need to choose a message format that both the client and server can understand. That format can be custom, framework-specific, or a standard messaging protocol.
STOMP — a simple, messaging protocol originally created for use in scripting languages with frames inspired by HTTP. STOMP is widely supported and well suited for use over WebSocket and over the web.
The WebSocket API enables web applications to handle bidirectional communications whereas STOMP is a simple text-orientated messaging protocol. A Bidirectional WebSocket allows a web server to initiate a new message to a client, rather than wait for the client to request updates. The message could be in any protocol that the client and server agree to.
The STOMP protocol is commonly used inside a web socket.
A good tutorial is STOMP Over WebSocket by Jeff Mesnill (2012)
STOMP can also be used without a websocket, e.g. over a Telnet connection or a message broking service.
And Raw WebSockets can be used without STOMP - Eg. Spring Boot + WebSocket example without STOMP and SockJs.
Note: Others have well explained what are both WebSocket and STOMP, so I'll try to add the missing bits.
The WebSocket protocol defines two types of messages (text and binary), but their content is undefined.
STOMP protocol defines a mechanism for client and server to negotiate a sub-protocol (that is, a higher-level messaging protocol) to use on top of WebSocket to define following things:
what kind of messages each can send,
what the format is,
the content of each message, and so on.
The use of a sub-protocol is optional but, either way, the client and the server need to agree on some protocol that defines message content.
Reference
TLDR; STOMP is a framework built on top of websockets, i.e. stomp utilizes websockets in the background. If you are thinking of building a notification/messaging system then use stomp.
https://stomp.github.io/stomp-specification-1.2.html
When I send a binary message from a Python server to a JavaScript client, an exception is thrown from JSON.parse at this codeline. I'm sending the message like this:
server.sendMessageHybi(myBinaryChunk, binary=True)
On the receiving end, the data field is holding a Blob object rather than a string. Wondering if this is a supported workflow, or if I'm doing something wrong.
You can send binary WebSocket messages from AutobahnPython and receive those on browser-side with pure WebSocket (you don't need AutobahnJS for that).
AutobahnJS is a WAMP implementation: RPC and PubSub over WebSocket. WAMPv1 uses text (JSON) messages for serialization and does not support (unencoded) binary payloads.
There are considerations for supporting binary payloads in WAMPv2 (https://github.com/tavendo/wamp/issues/4)
How does Twillio get to send so many messages via SMS? I am thinking about making my own service for my company for internal use, but I am trying to discover how they managed to do that in such a large quantity while still remaning afloat? Are they using some sort of connection with a large set of phones, and automagically sending the messages from their actual devices? Wouldn't their service provider frown upon that kind of volume?
They are at most using SMPP protocol to send SMS messages directly to their service. SMPP is a protocol widely used for sending mass (bulk) SMS messages between third-party and operator.
Excerpt from Wikipedia:
The protocol is based on pairs of request/response PDUs (protocol data
units, or packets) exchanged over OSI layer 4 (TCP session or X.25
SVC3) connections. PDUs are binary encoded for efficiency. Data
exchange may be synchronous, where each peer waits for a response for
each PDU being sent, and asynchronous,
See full Wikipedia article: Short Message Peer-to-Peer